Coke-cooling apparatus

ABSTRACT

A coke-cooling apparatus comprises a drum rotatable in a bath of cooling water about a generally horizontal axis and traversed from end to end by the coke to be cooled. The wall thickness of the drum or shell increases progressively from a central region toward each end.

4 United States Patent Waldmann et a1.

COKE-COOLING APPARATUS Inventors: Hans Waldmann, Trostberg;

Wilfried Schwarz, Wald Kraiburg; Manfred Bergfeld, Tacherting; HansJoachim Laupitz, Burghausen; Klaus Miiller, Mehring; Thaddeus J.Oleszko, Burghausen, all of Germany Linde Aktiengesellschaft,l-lollriegelskreuth, Germany Filed: Mar. 21, 1974 Appl. No.: 453,547

Assignee:

Foreign Application Priority Data Mar. 26, 1973 Germany 2315024 US. Cl.202/227; 165/90; 34/9;

34/134; 432/80; 432/85 Int. Cl Cl0b 39/00 Field of Search 165/87-90;

Primary Examiner-Charles .1. Myhre Assistant Examiner-Theophil W.Streule Attorney, Agent, or Firm-Karl F. Ross; Herbert Dubno [57]ABSTRACT A coke-cooling apparatus comprises a drum rotatable in a bathof cooling water about a generally horizontal axis and traversed fromend to end by the coke to be cooled. The wall thickness of the drum orshell in creases progressively from a central region toward each end.

9 Claims, 4 Drawing Figures aaauuuuuabuuuu Sheet 1 of2 US. Patent Nov.4, 1975 J. DQQIADBDDBQD [Z 5 BBQ US. Patent Nov. 4, 1975 Sheet 2 of23,917,516.

COKE-COOLING APPARATUS FIELD OF THE INVENTION The present inventionrelates to a coke-cooling apparatus and, more particularly, to anapparatus for cooling bulk material, especially coke, by indirect heatexchange with a coolant such as water.

BACKGROUND OF THE INVENTION The cooling of coke from a glowing state, asthis hot bulk material is received from a coke oven, has been effectedin the past in apparatus which carries out an indirect heat exchangebetween the coke and a coolant, especially water, through the wall of adrum rotatable about a horizontal axis and axially traversed by the hotcoke from an inlet end to an outlet end of the drum.

The drum is rotatable in a bath of water and it is formed with tubularpockets which increase the surface area in contact with the coke and thewater and entrain the water from the bath so that it flows substantiallyover the entire external surface of the rotating drum.

In conventional rotary coolers, the rotor drum or shell (alsogenerically described in the art as the socalled rotor) is of polygonalcross-section, usually with eight sides.

Because of the high temperatures of the coke, the shell is subjected tosubstantial temperature differentials not only between its exterior andinterior but from one end to the other, which causes rapid wear anddeterioration of the shell walls and the walls of the tubular pocketacross which the coke must pass. The thermal stresses limit the life ofthe apparatus and replacement of the drum is relatively expensive andresults in significant downtime of the system. Consequently, continuousoperation of the apparatus is seldom possible.

OBJECTS OF THE INVENTION It is the principal object of the presentinvention to provide an apparatus for the cooling of coke or other bulkmaterial in indirect heat exchange with a fluid coolant, especiallywater, in which deterioration of the vessel containing the bulk materialis limited and the useful life of the apparatus is increased beyondthose of the prior art.

Another object of the invention is to provide a coke cooler of thegeneral type described previously which has a longer useful life and agreater ratio of operating time to downtime.

Still another object of the invention is to provide a coke cooler ofrelatively low cost but improved efficiency.

SUMMARY OF THE INVENTION These objects and other which will becomeapparent hereinafter are attained in accordance with the presentinvention, in a cooler for bulk material, especially coke, whichcomprises an outer housing or vessel adapted to receive a bath of liquidcoolant, preferably water, and a drum, rotor or shell of generallyprismatic or polygonal-cross-sectional configuration in this vessel androtatable about a horizontal axis, the drum having an inlet end intowhich the bulk material is charged and an outlet end from which thecooled material is discharged. According to the present invention, therotor or drum comprises a sheet-metal shell of progressively increasingwall thickness from an intermediate region along its length toward theinlet and outlet ends.

According to another feature of the invention, the rotor, drum or shellis provided with a multiplicity of inwardly extending tubular pockets ofsheet-metal, e.g., sheet steel, which pick up, conduct and distributethe coolant over the periphery of the drum and increase the coolingeffectiveness, the wall thicknesses of these tubular pockets likewiseincreasing progressively from the intermediate region of the drum towardits ends.

The invention has been found to be surprisingly ef fective in increasingthe useful life of the drum or rotor because the increased materialthicknesses towards the ends compensate for the increased wear in theseregions. For example, the wear at the inlet end at which the glowingcoke is introduced at an extremely high temperature, e.g., 1,400C isproportionally higher because of the thermal stress and the corrosiveeffect of the hot bulk material than at "the intermediate regions inwhich the coke has been cooled to a significant degree. However ascooling progresses, the hardness of the coke increases and toward theend of the drum the abrasive character of the material is significantlyincreased over its abrasive effect at the temperatures of theintermediate region or zone so that the increased material thicknessesat this end likewise compensate for material wear. At the outlet thetemperature of the coke may be relatively low, e.g., C, although thehardness and abrasive character of the coke may be several times greaterthan that of the coke at the higher temperatures upstream in the drum.

Since the thickness of the drum is proportioned to the wear rates at thevarious regions along the length of the drum, the useful life of thedrum is increased since wear to failure occurs uniformly across the drumlength.

It has been found that this effect can be increased when, from the inletend of the rotor or drum to the outlet end thereof, the radial height ofthe tubular pocket is increased and their facing is likewise increasedwhile the widths of the pockets (parallel to the axis of the drum) isdecreased.

The smaller interpocket distances (closer spacing) and the widerconstruction of the pockets makes for a greater density of heat exchangearea per unit of axial length of the drum at the inlet end and hence anincreased heat exchange capacity at the regions at which the temperatureis higher. Furthermore, the low height of the pockets in the region ofthe inlet insures a more uniform distribution of the bulk material overthe interior of the drum and a more complete immersion of the pockets inthe water bath, again increasing the heat exchange properties of thedrum in this region. It has been found advantageous, for a unifromcooling of the shell, to provide the inlet end or outlet of the coolingpocket with shiftable covers which limit the throughflow of coolant andthereby permit a uniform temperature gradient to be maintained over thelength of the drum and prevent thermal stresses which result fromsignificant temperature differentials and promote wear.

Since the tubular cooling pockets within thedrum come into directcontact with hot or cooled coke and sufficient or abrasive hard coke, ithas been found to be advantageous to protect the surfaces of the coolingpockets turned toward the axis of the drum with protective aprons orcopings. The latter may be composed of steel and may be angles or steelplates which, to avoid the effect of thermal stress, are secured atsingle points in the middle of each plate section to the cooling pocket.

Because of the relatively considerable mass of the rotor and the coketraversing same it has been found to be advantageous to avoid thedevelopment of stress at the cooling pockets and elsewhere in the drumby distributing the bulk material uniformly over the interior of thedrum. This is effected, according to the invention, by providing theinlet of the drum as a conically widening shell which may be formed witha plurality of cooling pockets which also act to promote the advance ofthe material into the interior of the drum mentioned as do advance in aconventional bulk-material treatment device.

BRIEF DESCRIPTION OF THE DRAWING The above and other objects, featuresand advantages of the present invention will become more readilyapparent from the following description, reference being made to theaccompanying drawing in which:

FIG. 1 is a diagrammatic vertical section wherein, because of the smallsize of the drawing, wall thicknesses have not been shown;

FIG. 2 is a section taken along the line IIII of FIG. 1 and drawn to anenlarged scale;

FIG. 3 is a detail cross-section view through a portion of the drum ofFIG. 1 showing the relationships of the wall thickness and coolingpockets to the drum in greater detail; and

FIG. 4 is an elevational view of the portion of the drum, drawn to alarger scale than FIGS. 1 and 2.

SPECIFIC DESCRIPTION The coke cooler shown in the drawing comprises avessel 1 for water bath 3 receiving a rotor or drum 2 of octagonalcross-section (see FIG. 2).

The rotor or drum 2 dips into the water 3 to a substantial extent, i.e.,the greater part of the radius of the drum which may also be cylindricalor of another polygonal cross-section as desired.

The rotor or drum 2 comprises an outer shell 6 having a horizontal axisand formed at one end with a discharge duct 6 and the opposite end witha conical inlet duct frustoconically diverging in the direction of thedrum 2. At this duct 5 there are provided a plurality of chordal coolingpockets 7 which permit intensive cooling by contact with the water bathand limit the formation of thermal stresses and cracking between thedrum and the inlet duct 5. The inlet duct 5 and the outlet duct 6 can beflanged as shown for the duct 5 or welded as shown in duct 6, to thedrum.

Ahead of the inlet duct there is provided a water cooled inlet chute 8which leads the coke from the coke furnace into the inlet duct, thechute representing inlet means, etc., according to the principles of thepresent invention. 1

The discharge duct 6 is provided with discharge means for drawing thebulk material from the system in the form of a conveyor wall which opensinto a discharge chamber or hopper 9 which may be composed in whole orin part of wire-reinforced glass and is provided with an automaticallyoperable emergency door .11 for relieving pressure within the system,e.g., in the case of explosion or the development of a gas condition.The door 11 may by hydraulically operable.

When a greater heat exchange area is desired, the level of the waterbath 3 can be raised and, when a reduced heat exchange capacity isdesired, the water bath level may be lowered. To permit raising andlowering of the level beyond the region in which the drum is jour- 4naled, the rotor or drum 2 is rotatably sealed relative to the vessel 1with sealing rings 12 or 13 of rubber or other material which permitsrotation but prevents escape of water.

The drum 2 is formed with a multiplicity of tubular cooling pockets 14which extend along chords of the device and open the opposite walls ofthe drum. The pockets thus lie transversely to the drum axis and can besealed along the inner walls of the drum.

According to the invention, the sheet-metal thickness of the shell 4 andof the cooling pockets 14 increase from an intermediate region of therotor 2 in the direction of the inlet 15 and the outlet 16. The heightof the cooling pockets 14 perpendicular to the rotor axis and thespacing of the cooling pockets 14 from one another increase from theinlet to the outlet while the width of the cooling pockets decreasesfrom the inlet to the outlet.

The open .ends of the cooling pockets l4 lie at the surface of the shell4 and are provided with slidable covers 17 which permit control of thewater flow through the pockets during rotation.

The arched side of the cooling pockets l4 turned toward the rotor axisare protected by angle members 18 of steel weld only at centrallocations to the cooling pockets. The welding locations are representedby dots 18 in FIG. 2.

Above the rotor, there is disposed a supply device 19 for promoting heatexchange and thereby reducing thermal stress while increasing thethroughput of the apparatus. To reduce water loss, a dephlegmator 20 isprovided in the vent to the vessel 1 for condensation of water from thegas phase above the water bath.

Further cooling of coke, the glowing bulk product is introduced throughthe inlet chute 8 and the inlet duct 5 to pass over the cooling pocketsin the main portion of the drum 2 and subject the coke to indirect heatexchange with the water bath. The water passes through the pockets l4and reduces the temperature of the coke so that cooled coke is withdrawnvia the discharge duct 6 and the worm 10 to collect in the hopper 9. Therate of operation of the worm 10 controls the level of coke within thedrum.

FIGS. 3 and 4 show the features of the invention in somewhat greaterdetail. From FIG. 3, for example, it will be apparent that the thicknessof the shell 4 of the drum 2 decreases from a thickness T to a thicknesst from the inlet end toward an intermediate region and a correspondingdecrease in thickness takes place from the discharge end to theintermediate region. Described otherwise, the wall thickness of thesteel shell 4 increases from the thickness t at an intermediate locationL to a thickness T toward each end. The cooling pockets or tubes 14which are welded at 14' to the wall 4 and along their peripheries 14" tothe adjacent wall 4 of the shell, have widths measured parallel to theaxis of rotation of the drum which decrease from a width W to, say awidth w progressively from the inlet side to the discharge side of thedrum.

The height of the cooling pockets or tubes 14, as measured radially withrespect to the axis of rotation of the drum may increase from a height hto the height H, etc., progressively from the inlet side to thedischarge side of the drum and the wall thicknesses of the pockets maydecrease from the thickness 1 toward each end. The thicknesses of theprotective angle members 18 may likewise decrease from a thickness t" toa thickness T" from the intermediate region toward each end of the drum.The single weld point for each flange 18a, 18b of the protective members18 is represented at 18 in FIG. 3.

FIG. 4 was the opening at which the pockets communicate with theexterior in the walls 4' and 4" of the drum 4. These openings can beblocked completely or partly by the slidable plates 17 which are guidedin channels 17' parallel to the axis of rotation of the drum and aremovable as represented by the arrows to completely or partially overliethese openings.

The distance between the pockets 14 may increase from a relatively smalldistance d at the inlet end to larger distances D, etc., toward thedischarge end of the drum (FIG. 3). The discharge worm may be verticallyadjustable, i.e., of adjustable height, if desired to control the levelof material in said drum.

What is claimed is:

1. In a coke-cooling apparatus for bulk material comprising a vesselforming a water bath, an elongated drum rotatable about a horizontalaxis in said vessel and dipping into said water bath; the improvementcomprising a multiplicity of tubular cooling pockets formed on the wallof said drums, said drum having a sheet-metal wall, the wall thicknessof said drum and said cooling pockets increasing progressively from anintermediate region along the length of said drum toward the oppositeends thereof.

2. The apparatus defined in claim 1 wherein said cooling pockets are ofincreasing radial dimension as measured with respect to the axis ofrotation of said drum and increasing inter-pocket spacing parallel to 6the axis of the drum from an inlet end thereof toward a discharge endthereof, the width of said pockets as measured parallel to said axisdecreasing from said inlet end toward said discharge end.

3. The apparatus defined in claim 2, further comprising slidable coverson said drum for controlling the fluid through-flow of said pockets.

4. The apparatus defined in claim 3 wherein said pockets have surfacesturned toward said axis, said surfaces turned toward said axis beingprovided with we arreducing aprons.

5. The apparatus defined in claim 4, further comprising a frustoconicalinlet duct widening toward and communicating with said drum at saidinlet end.

6. The apparatus defined in claim 5 wherein said inlet duct is providedalong its periphery with a multiplicity of cooling pockets.

7. The apparatus defined in claim 6 wherein'said discharge end isprovided with a discharge duct leading through said vessel, said ductsbeing sealedrelative to said vessel with respective sealing rings.

8. The apparatus defined in claim 4 wherein said discharge endcommunicates with a collection chamber for the cooled material, saidcollection chamber being formed with an automatic operable emergencydoor.

9. The apparatus defined in claim 4, further comprising a discharge wallat said discharge end for removing cooled material from said drum, saiddischarge wall being of adjustable height to control the level ofmaterials in said drum.

1. IN A COKE-COOLING APPARATUS FOR BULK MATERIAL COMPRISING A VESSELFORMING A WATER BATH, AN ELONGATED DRUM ROTATABLE ABOUT A HORIZONTALAXIS IN SAID VESSEL AND DIPPING INTO SAID WATER BATH, THE IMPROVEMENTCOMPRISING A MULTIPLICITY OF TUBULAR COOLING POCKETS FORMED ON THE WALLOF SAID DRUMS, SAID DRUM HAVING A SHEET-METAL WALL, THE WALL THICKNESSOF SAID DRUM AND SAID COOLING POCKETS INCREASING PROGRESSIVELY FROM 2.The apparatus defined in claim 1 wherein said cooling pockets are ofincreasing radial dimension as measured with respect to the axis ofrotation of said drum and increasing inter-pocket spacing parallel tothe axis of the drum from an inlet end thereof toward a discharge endthereof, the width of said pockets as measured parallel to said axisdecreasing from said inlet end toward said discharge end.
 3. Theapparatus defined in claim 2, further comprising slidable covers on saiddrum for controlling the fluid through-flow of said pockets.
 4. Theapparatus defined in claim 3 wherein said pockets have surfaces turnedtoward said axis, said surfaces turned toward said axis being providedwith wear-reducing aprons.
 5. The apparatus defined in claim 4, furthercomprising a frustoconical inlet duct widening toward and communicatingwith said drum at said inlet end.
 6. The apparatus defined in claim 5wherein said inlet duct is provided along its periphery with amultiplicity of cooling pockets.
 7. The apparatus defined in claim 6wherein said discharge end is provided with a discharge duct leadingthrough said vessel, said ducts being sealed relative to said vesselwith respective sealing rings.
 8. The apparatus defined in claim 4wherein said discharge end communicates with a collection chamber forthe cooled material, said collection chamber being formed with anautomatic operable emergency door.
 9. The apparatus defined in claim 4,further comprising a discharge wall at said discharge end for removingcooled material from said drum, said discharge wall being of adjustableheight to control the level of materials in said drum.